JP2777286B2 - Vaporizer - Google Patents

Description

The present invention relates to a carburetor for mixing with combustion air to supply a mixture to supply fuel gas to power a reciprocating internal combustion engine.

An engine is used to power a vehicle, for example, a ground vehicle, or a static engine is used to drive a machine, for example, an electric power generator. Such a generator is used in a heat power system (CHP) known per se.

To ensure that reciprocating internal combustion engine equipment supplied with fuel gas, e.g., natural gas, minimizes exhaust emissions and provides the greatest gain in terms of maximizing power output and efficiency: The gas must be mixed with the combustion air to simultaneously satisfy the three criteria: The gas / air mixing method must (1) ensure complete homogeneity, (2) minimize flow restrictions, and (3) maintain a constant air-fuel ratio over the entire range of working flow. Must give.

It is an object of the present invention to provide a carburetor that is configured to provide a substantially homogeneous mixture of fuel gas and air, and that further reduces flow restrictions and provides a substantially constant air-fuel ratio over the entire range of working flow. It is in.

According to the present invention, there is provided a carburetor for supplying a fuel gas for powering a reciprocating internal combustion engine by mixing with a combustion air to supply a mixture, the venturi flow path for a flow of the combustion air. An obstruction disposed in the throat and spaced from the wall of the throat by a gap that generally surrounds the throat; and slot means in the wall of the Venturi flow path for fuel to exit into the Venturi flow path. Wherein the slot means comprises:
A first slot facing the gap at the throat, and extending circumferentially along a wall of the throat to substantially surround the obstruction; and a first slot facing the gap at the throat; and A second slot extending circumferentially along the outer wall of the obstruction and substantially surrounding the obstruction; and flow passage means for supplying fuel gas to the slot for gas to exit the throat from the slot. And a vaporizer characterized by having:

In one embodiment of the vaporizer, the first part of the obstruction is upstream of the second slot, with respect to the general direction of air flow from one end of the venturi through the venturi to the other end, and the obstruction The second part of
Downstream of the second slot and orthogonal to the general direction of the air flow, the first portion of the obstruction has a cross-sectional area that increases along the general direction of the air flow;
The second portion of this obstruction preferably has a decreasing cross-sectional area along the general direction of the air flow.

The present invention is further described by way of example with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view taken along line II of FIG. 3 of a first embodiment of a vaporizer formed according to the present invention.

 FIG. 2 is a partial cross-sectional view taken along line II-II in FIG.

FIG. 3 is a front end view of the scale of FIG. 2 on an enlarged scale along the direction of arrow III of the vaporizer of FIG.

FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3 that is enlarged with respect to FIG.

FIG. 5 is a longitudinal sectional view similar to FIG. 1 of a second embodiment of the vaporizer formed according to the present invention.

In the accompanying drawings, like reference numbers identify similar or corresponding parts.

1 to 4, a carburetor 2 for supplying a fuel gas, for example a mixture of natural gas and air, to a reciprocating internal combustion engine (not shown) comprises a Venturi tube 4 having an air inlet end 6. Combustion air flows into the Venturi tube from the general direction 8 through the air inlet end 6 and has a throttle portion 10 attached to the Venturi tube.

The Venturi tube 4 is provided in the two tubular components 12 and 14 and further comprises a tapered Venturi section defined by an inner wall 16, a Venturi throat defined by an inner wall 18, and a Suehiro Venturi section defined by an inner wall 20. The walls 16, 18 and 20 are surfaces of revolution about a Venturi axis 22, and the throat 18 is substantially cylindrical.

The throttle section 10 has a rotatable throttle valve 24 (known per se) that operates within a cylindrical tube section 25,
The cylindrical tube section 25 has mounting outer end flanges 26, 28 with axial passages for receiving tightening bolts, such as, for example, bolts 30 having nuts 32, and the nut 32 attaches the flange 28 to the mounting of the component 14. It is fixed to the end flange 34.

A generally teardrop-shaped obstruction 36 is disposed on the throat 18, with its front end extending into the tapered portion 16 and its rear end extending into the divergent portion 20. The obstruction 36 is a substantially circuit body centered on an axis coinciding with the Venturi tube axis 22. The obstruction 36 has, at its front or at its upstream end facing in the direction of air flow 8, a ball segment which is substantially hemispherical in FIGS. 1 to 4 and thus in the direction of air flow. The cross-sectional area along which is perpendicular to the direction of air flow increases. Obstruction 36 is the front part
Downstream of 38 there is a generally conical rear portion 40 with the top located at the rearmost portion, so that the rear portion 40 has a reduced cross-sectional area along the direction 8 of air flow and perpendicular to the direction of air flow.

The front portion 38 has a rearwardly extending axial spindle 42 threaded into an axial bore 44 in the rear portion of the obstruction 36.

Venturi 4 walls 16, 18, 20 and obstruction
A tubular gap 46 between the 36 outer walls completely surrounds the obstruction. Gap 46 is narrowest at 48 opposite the rearmost or downstream end of hemisphere 38. Due to the shape of the obstruction 36 and the Venturi tube 4, the tubular gap 46 is itself an annular cross-section Venturi tube having an annular throat 48.

A narrow slot 50 opens to the throat 48. The slot 50 is a continuous annular slot extending circumferentially along the wall 18 and surrounding the obstruction.
A continuous tubular channel 52 opens into the slot 50 and a short tubular pipe 54 faces this channel 52 for connection to the supply of fuel gas. The slot 50 is configured between adjacent end faces of components 12 and 14 having end mounting outer flanges 56 and 58, the outer flanges 56 and 58 having an axial passage for receiving a tightening bolt 60 and a bolt 60. Is component 12 and
It has a nut 62 for fixing the 14 together. One or more annular distance washers or shims 64 (only one shown in FIGS. 1 and 2) are between the flanges 56 and 58 and, depending on the thickness or number of shims 64 used, the axis of the slot 50 Determine the thickness in the direction.

A pair of diametrically opposed radially extending arms 66 mounted on wall 20 support obstruction 36 in place. As shown in FIG. 4, each arm 66 has a teardrop cross-sectional shape, with a point 68 downstream in the direction of the airflow 8 relative to the rounded end.

Another narrow slot 70 opening to the throat 48,
Facing slot 50. Obstruction 36
The wall slot 70 is a continuous annular slot that extends circumferentially along the obstruction wall to surround the obstruction. Obstruction
A continuous annular path 72 of the rear portion 40 of 36 opens into slot 70. Each arm 66 has a through flow path 74 that has one end facing the flow path 52 and the other end opening toward the flow path 72. The slot 70 is formed between adjacent end faces of the front and rear portions 38, 40 of the obstruction 36. One or more annular distance washers or shims 76 (only one shown in FIGS. 1 and 2) are between these end faces, and the thickness or number of shims 76 determines the axial width of slot 70. Used for

In use, pipe 54 is supplied with fuel gas in any manner known per se, for example, gas reaching pipe 54 may be supplied at a desired predetermined pressure from a pressure regulator.

Gas supplied to pipe 54 exits throat 48 via both slots 50 and 70. When the vaporizer is ready for use, the shims 64 and 76 used are assured that the flow rate of fuel gas per slot length from slot 50 is approximately the same as that from slot 70. You can choose the number.

The inflowing air is forced to flow through the narrow channel 48. With this design, the momentum of the fuel gas flow is sufficient to carry the gas to the center of the incoming air column, since the fuel gas is introduced into the air from both sides of the flow path 48, and thus, within the flow path 48. Ensures that the likelihood of gas permeation throughout the annular air is good. In addition, a narrow annular gap 48
With the use of, the velocity of the air is significantly increased, thereby increasing the turbulence as an aid to the mixing of the fuel gas and air. Thus, the aforementioned vaporizer design increases the likelihood that more homogeneous mixing will occur. Walls 16, 18 and Obstruction
The tapered portion of the tubular venturi 46 between the front portion 38 of 36 increases the velocity of the air at the throat 48 so that the amount of fuel gas captured is directly proportional to the amount of air.

This provides the necessary air-fuel ratio control for a wide range of air flows. Also, the divergent outflow portion of the tubular venturi 46 between the conical portion 40 of the obstruction 36 and the wall 20 achieves high pressure recovery, thus reducing total pressure loss.

In FIG. 5, the forward or upstream portion 38 of the obstruction 36 is of a generally conical shape with its apex facing the direction 8 of the air flow. Again, in FIG. 5, the obstruction 36 is a rotator about an axis coinciding with the axis 22 of the venturi 4.

A reciprocating internal combustion engine supplied with a fuel gas / air mixture can be used to drive a vehicle, or to drive a generator that is part of a CHP system. The heat generated by the internal combustion is extracted and uses heat exchange means (known per se) for useful purposes, such as space and / or process heating.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Slowly John UK Bristol BS 156 RH Oldland Common Oakley Gardens 20 (72) Inventor Charlton Stephen John United States 47201 Columbus Kinney Lane 694 (58) (Int.Cl. ⁶ , DB name) F02M 21/04 F02M 19/02

Claims (5)

(57) [Claims] 1. A carburetor for supplying a mixture by mixing with combustion air to supply a fuel gas for motively driving a reciprocating internal combustion engine, comprising a Venturi flow path for a flow of combustion air. An obstruction disposed on the throat and spaced from the wall of the throat by a gap that generally surrounds the obstruction, wherein the obstruction rotates substantially about an axis coinciding with the axis of the Venturi flow path. A first slot that opens toward the gap with the throat and extends circumferentially along the wall of the throat to substantially surround the obstruction; and faces the gap with the slot. And a second slot extending circumferentially along the outer wall of the obstruction and substantially surrounding the obstruction. The width of the first and / or second slots along the axis of the venturi can be adjusted to change the size of the slots and further to allow gas to exit the throat from the slots. A vaporizer having flow path means for supplying gas to said slot. 2. The carburetor of claim 1, wherein said first and second slots are substantially opposite each other across said gap. 3. The carburetor according to claim 1, wherein the obstruction has an outer surface that is a substantially rotational surface about the axis of the venturi. 4. The apparatus according to claim 1, wherein the first part of the obstruction is in the direction of the airflow through the venturi.
Upstream of the slot, the second of said obstruction
A portion is downstream of the second slot, and orthogonal to the axis of the venturi, the first portion of the obstruction has a cross-sectional area that increases along a direction of air flow, and a second portion of the obstruction. 4. A carburetor according to claim 3, wherein the two parts have a decreasing cross-sectional area along the direction of air flow. 5. A reciprocating internal combustion engine in which the carburetor according to claim 1 is combined.